mmc: atmel-mci: restore dma on AVR32

Commit ecb89f2f5f3e7 ("mmc: atmel-mci: remove compat for non DT board
when requesting dma chan") broke dma on AVR32 and any other boards not
using DT.  This restores a fallback mechanism for such cases.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index b4cb3bd..6e90617 100644 (file)
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -1321,6 +1321,21 @@ static struct clk atmel_mci0_pclk = {
        .index          = 9,
 };
 
+static bool at32_mci_dma_filter(struct dma_chan *chan, void *pdata)
+{
+       struct mci_dma_data *sl = pdata;
+
+       if (!sl)
+               return false;
+
+       if (find_slave_dev(sl) == chan->device->dev) {
+               chan->private = slave_data_ptr(sl);
+               return true;
+       }
+
+       return false;
+}
+
 struct platform_device *__init
 at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
 {
@@ -1355,6 +1370,7 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
        slave->sdata.dst_master = 0;
 
        data->dma_slave = slave;
+       data->dma_filter = at32_mci_dma_filter;
 
        if (platform_device_add_data(pdev, data,
                                sizeof(struct mci_platform_data)))

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index bf62e42..070dffc 100644 (file)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2280,6 +2280,23 @@ static int atmci_configure_dma(struct atmel_mci *host)
 {
        host->dma.chan = dma_request_slave_channel_reason(&host->pdev->dev,
                                                        "rxtx");
+
+       if (PTR_ERR(host->dma.chan) == -ENODEV) {
+               struct mci_platform_data *pdata = host->pdev->dev.platform_data;
+               dma_cap_mask_t mask;
+
+               if (!pdata->dma_filter)
+                       return -ENODEV;
+
+               dma_cap_zero(mask);
+               dma_cap_set(DMA_SLAVE, mask);
+
+               host->dma.chan = dma_request_channel(mask, pdata->dma_filter,
+                                                    pdata->dma_slave);
+               if (!host->dma.chan)
+                       host->dma.chan = ERR_PTR(-ENODEV);
+       }
+
        if (IS_ERR(host->dma.chan))
                return PTR_ERR(host->dma.chan);
 

diff --git a/include/linux/atmel-mci.h b/include/linux/atmel-mci.h
index 9177947..e753062 100644 (file)
--- a/include/linux/atmel-mci.h
+++ b/include/linux/atmel-mci.h
@@ -2,6 +2,7 @@
 #define __LINUX_ATMEL_MCI_H
 
 #include <linux/types.h>
+#include <linux/dmaengine.h>
 
 #define ATMCI_MAX_NR_SLOTS     2
 
@@ -37,6 +38,7 @@ struct mci_slot_pdata {
  */
 struct mci_platform_data {
        struct mci_dma_data     *dma_slave;
+       dma_filter_fn           dma_filter;
        struct mci_slot_pdata   slot[ATMCI_MAX_NR_SLOTS];
 };